Grinding Cycle Speed Variation for Vibration Control
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Solution Overview
Problem
Conventional grinding processes experience instabilities and vibrations due to abrupt changes in grinding speeds, leading to uneven surface finishes and failure to achieve required tolerances in cylindrical and centerless grinding operations.
Innovation Solution
A method that continuously varies the rotation speed of the work piece, the feed speed between the grinding wheel and work piece, and the grinding wheel's rotation speed throughout the grinding cycle, using signals like ramps or sinusoidal functions, to maintain surface quality and reduce vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the approximation feed speed is varied in a step-like and constant manner during different stages, then the grinding cycle can be optimized, but abrupt jumps between stages cause vibrations and uneven surface finish
Solution Approach 1:
The patent applies dynamics by transitioning from constant step-like speed variations to continuous dynamic speed variations. The approximation feed speed, work piece rotation speed, and grinding wheel rotation speed are all varied continuously throughout the grinding cycle using sinusoidal or ramp functions, eliminating abrupt jumps and maintaining surface quality while optimizing productivity.
Solution Approach 2:
The patent implements parameter changes by continuously varying multiple speed parameters (approximation feed speed, work piece rotation speed, grinding wheel rotation speed) simultaneously. These parameters are changed according to continuous functions (sinusoidal or ramp) rather than discrete steps, resolving the contradiction between productivity optimization and surface finish quality.
2Stability of the object's composition
If the rotation speed of the work piece is varied according to a sinusoidal function, then vibrations are partially minimized, but the approximation feed speed remains step-like causing surface finish issues
Solution Approach 1:
The patent merges the variation of multiple speed parameters (work piece rotation speed, approximation feed speed, and grinding wheel rotation speed) into a unified continuous variation strategy. All three parameters are varied simultaneously according to continuous functions, combining their effects to eliminate vibrations and ensure surface quality, rather than varying only one parameter in isolation.
Solution Approach 2:
The patent extends the dynamic approach by making all three speed parameters continuously variable rather than keeping two of them constant. This comprehensive dynamic control ensures that vibration reduction is maintained while preventing new surface finish issues from step-like changes in the approximation feed speed.
3Loss of time
If multiple grinding speeds are continuously varied in a combined manner, then grinding cycle time is reduced and vibrations are eliminated, but the process complexity increases
Solution Approach 1:
The patent employs periodic action by using sinusoidal functions to vary the grinding speeds. This periodic variation creates a rhythmic, predictable pattern that reduces vibrations and optimizes the grinding cycle. The sinusoidal nature of the speed variations provides a systematic approach that, while more complex than constant speeds, follows a well-defined mathematical pattern that can be implemented through standard control systems.
Solution Approach 2:
The patent implements continuity of useful action by ensuring that all speed parameters vary continuously without interruption or abrupt changes throughout the entire grinding cycle. This continuous variation maintains stable cutting conditions, eliminates vibrations, and optimizes material removal rates, reducing cycle time while the complexity is managed through the use of standard continuous control functions.
Data Source
AI summary
The present invention refers to a method of grinding, in which a continuous and combined variation of at least one rotation speed (Nw) of a ground work piece (P) and one approximation feed speed (Vf) between a grinding wheel (M) and the ground work piece (P) is performed throughout an entire grinding cycle.